This invention relates to an auger for a combine header, and, in particular, to an auger allowing longer length combine headers and lower maintenance combine headers.
In the past, the maximum combine header length that was available was approximately 30 feet. It was found that once a header went beyond 30 feet, the auger used to convey cut crop stalks to the central portion of the header and thereafter into the separator machinery of the combine would not operate efficiently. In particular, the center auger tube of most of the combine headers in the past was at the very least approximately one third of the overall diameter of the auger. The overall diameter of the auger is the distance from the edge of the top of the flights of the augers through the center tube to the lower edge of the flights. More specifically, in a GLEANER combine header manufactured by AGCO, a header auger would have a 30-inch overall diameter. Sixteen inches of that overall diameter would be comprised of the diameter of the inner tube. Thus, the center tube of the GLEANER header would be approximately 53.3 percent of the overall diameter of the auger. In a Case International Harvester combine, with an overall auger diameter of 24 inches, the center tube would comprise approximately 14 inches of the overall diameter. Thus, in a Case International Harvester header, the center tube is approximately 58.3 percent of the overall diameter header. In a John Deere combine header having a 24-inch overall diameter, the central tube would comprise approximately sixteen inches of the overall diameter. Thus, in a John Deere combine the center tube comprised approximately 67 percent of the overall diameter. The structure of these prior art combine headers do not appear to allow the construction of combine headers beyond 30 feet. More specifically, in longer combine headers, oftentimes the crop stalks are not conveyed adequately to the central portion. In fact, some of the stalks with the heads still attached flow over the top of the auger and sometimes out of the header. Still further, oftentimes the stalks and headers are not conveyed in a continuous manner to the central portion, thus resulting in large clumps running to the central portion and being ingested into the separating cylinder portion of the combine, often resulting in xe2x80x9csluggingxe2x80x9d of the combine.
An additional disadvantage of prior art combines having long length is the maintenance associated with the retractable finger mechanisms in the very central portion of the auger. The fingers move in and out from the central portion of the combine auger tube in a retracting manner. There is a well-known mechanism within the auger tube which allows this retraction and extension. More specifically, the fingers will extend as the portion of the auger they are located on is rotated toward the bottom platform of the header. Thereafter, they will retract as they reach the farthest position away from the bottom of the header. The mechanism to accomplish this extension and retraction is rather complex and has a variety of bearings associated therewith. Additionally, the location of the retraction and extension mechanism in the center of the combine auger is often difficult to access in order to perform maintenance or repairs.
Therefore, a combine auger is needed which alleviates the problems with the prior art combine augers discussed above.
One object of the present invention is to provide a combine auger which allows increased length of combine headers.
Another object of the present invention is to provide a combine auger header which enhances the efficiency with which stalks and heads of crops are conveyed to the central portion of the header and fed into the separator portion of the machine.
A further object of the present invention is to provide a header auger for a combine which is easy to maintain and has a minimum of moving parts.
A still further object of the present invention is to provide a header auger for a combine which prevents carryover of crop stalks during the conveyance from the outer edges of the header to the interior portion wherein they are fed to the separator mechanism of the combine.
In order to accomplish the above objectives, a header auger for a combine is provided which is rotatably positioned in a combine header. The auger includes a central tube having an outer cylindrical surface and having a first diameter. The auger includes flighting extending from an outer surface of the central tube and the flighting has an outermost edge and a screw-type orientation around the central tube. An auger diameter is defined as the diameter extending from a top edge of the flighting to the bottom edge of the flighting. The first diameter of the central tube is approximately one-fourth of the overall auger diameter.